Dave and his new wife Linda go flying together sometimes. He escapes to the sky whenever he can; she tags along. Sometimes they fly from Melbourne up to Echuca on the Murray River, three hours away by car, for lunch.

"Who else does that?" Dave Jacka asks. Then he repeats a mantra: "You are only limited by what you think you can do."

Jacka is a quadriplegic in a wheelchair. He is 44 and rode a Honda CB250 motorbike into a tree late one winter's night on a suburban cigarette run when he was 19. He broke his neck, lost the use of all four limbs and his lungs collapsed. He spent three months in intensive care and six in rehabilitation.

"Proof that smoking's bad for your health," Jacka says.

He can move nothing below his armpits except for a slight bit of arm movement. He can not put his hand on his head, for example. Seeing him work his mobile phone is like watching an illusionist pull a card trick; it slides and fumbles and somehow comes out true. He has carers in his Melbourne house up to six hours a day, getting him out of bed and back in and cleaning and cooking.

Yet he can fly. In April he aims to be the first person to circumnavigate Australia solo on a mission he has called "On A Wing and a Chair". He's not raising money for charity but raising awareness: he says disabled people can do surprising, amazing things despite copping negativity and discrimination and despite also suffering from higher rates of depression, mental illness and suicide than the able-bodied population.

Jacka began flying only after he had lost the use of most of his body. "When I was a kid I was mad on planes," he says. "I'd collect Qantas models and send letters to them to get information on the planes, and I remember at primary school my bedroom walls were covered in pictures of planes. I always wanted to fly."

After his crash he saw microlight aircraft – "like flying a motorbike" – at an airshow and got one and modified it and got right into it, flying over Uluru and Lake Eyre.

But quadriplegia means you lose control of body temperature, and after a few gruelling flights getting far too cold and taking ages to warm up he decided to fly with a cockpit and a heater.

Flight has a metaphysical appeal for him, of course. He leaves his earthly restrictions behind. "For me it's freedom. Launch myself off and away I go like a wedge-tailed eagle soaring in the sky. I'm no different to anyone else up there. In fact, I'm better than most."

He owns a Jabiru J230 aeroplane with room behind the two seats for his wheelchair. The modifications, which he did himself with an engineer mate before they were approved by the Bundaberg-based manufacturer, mean he can control the plane using shoulder strength and also his mouth – he puts his wrists into clamps on the levers for his rudders and sucks or blows into a tube attached to his headset for throttle. The brakes work by pneumatics through a toggle switch.

Simple. That's how Jacka sees it anyway – no problem. He was an apprentice carpenter before his crash. His father Brian Jacka, a psychologist, says he was always outdoorsy and practical and his dream was to have a ute with a dog on the back and build houses and travel. Things changed radically, "but there was never any thought of blaming life and the universe for what happened".

Jacka retrained himself in mechanical engineering. Now he works for Melbourne Water as manager – wheeling around on project sites a lot of the time "seeing things getting made".

He played wheelchair rugby, or "murderball", for Australia at the 1995 world championships and the 1996 Paralympics. He won a gold medal for Australia for disabled shooting at the 1991 Oceania shooting championships. Since his crash, he also snowskied and kayaked.

His secret both mentally and physically was to break down goals into increments. His first was to be able to put a jumper on by himself. Then feed himself. Get into bed. Drive. Brian Jacka says when his son started driving, he had to work out how to dismantle his wheelchair and get it in the car, a process towards independence that took months, in which he reduced the time it took him down from a hour to about five minutes. "That was inspirational to watch," Brian Jacka says. "It was no mean feat."

Jacka's wife Linda Sands says he constantly needs goals. "He needs to be doing something all the time or working towards something. Flying is Dave's passion. If he hasn't had a fly he gets toey and goes up and comes back happy."

She says his family (Jacka has four sisters) all have a determination about them. Jacka is related to Albert Jacka, the first Australian to get a Victoria Cross in the First World War, for bravery at Gallipoli.

Jacka met Linda online. She's Dr Sands – a former heart research scientist who now has a business installing prayer and meditation rooms in corporate offices. She's able-bodied.

"I'd never been out with a man in a wheelchair before," she says. "It changes the way your life is, that's for sure. But he's hilarious – so funny. A great guy. We hit it off straight away. To me he typifies the Aussie character, he's a real Jacka.

"The way I see him," she says, "is as an independent, whole person who needs a bit of help from carers to be that."

Her role is partner, not carer. The carers turn up at maybe 6am to get him out of bed every day; she might sneak off to the spare room for more kip. They're planning on trying for kids, through IVF. Quadriplegic men generally cannot ejaculate.

I met Jacka a few times. I met Sands once, not long before they got married in November. This was out at Tooradin Airport near Melbourne, where he keeps his plane. After an hour or two out there they had to go back to the city because they were having a rehearsal for their wedding dance. The wedding itself was on a lagoon in Thailand; both of them were making jokes about the sand and the wheelchair. Jacka said he had organised some sort of plank.

He's so upbeat that at first you suspect it's bluff, but this doesn't seem to be the case. Sands says her husband's family would pull him up if he wasn't genuine about his feelings.

When he gives talks at schools he shows a Powerpoint of himself as a kid on a billy-cart, as a handsome young man with a surfboard and then mangled in hospital with the medieval-looking head-tongs and a rope and weight holding his head in place, and tubes everywhere, including one from his neck so he can breathe, his skin yellow, his eyes shut firm.

His one true dark moment, he says, was when he first went into rehabilitation in hospital. He was wheeled into a room by a nurse, who then left. He was facing a pale blue wall. "I thought 'I can't do anything except sit and stare at this wall,' " he says. "It was a huge shock. I balled my eyes out."

Now his goal is to fly around Australia on his own. The trip will have 21 stops for donated accommodation; some legs will be three hours, some will be six hours. He'll go around Tasmania, Cape York, Cape Byron and the westernmost point of Western Australia, Steep Point.